Automatic regulating valve



Sept. 23, 1930. J. DEWRANCE AUTOMATIC REGULATING VALVE Filed Mardh l9 1929 2 Sheets-Sheet Patented Sept. 23, 1930 UNITED STATES JOHN DEV/RANGE, 0F SOUTHWARK, Lon non, ENGLAND AUTOMATIC saccharine Application filed March 19, 1929, Serial No.

' The present invention relates to automatic regulating valves applicable, for example, as reducing valves or for the control of the supply of fluid in accordance with pressure variation. i

A regulating valve in accordance with this invention comprises a ,main valve adapted to be opened by a spring or its equivalent, acting in opposition to a fluid pressure under control of a pilot valve essentially similar in its action to the main valve, but provided with a balancing device. f

In order that the invention may be clearly understood and readily carried into eii'ect, it will nowbe described more fully with reference to the accompanying drawing, which illustrates, by way of example, two forms of valve in accordance with the invention and in which Figure l is alongitudinal section of the main valve,

Figure 2 shows the main valve in side view and the pilot valve in longitudinal section,

Figure 3 is a plan view of the main and pilot valves and Figure 4 depicts a modified form of pilot valve in longitudinal section.

In applying the invention to a reducing valve as shown in Figures 1, 2, and 3, the main valve may be constituted by an ordinary lift valve 1 arranged to pass fluid from the high-pressure inlet 2 to the low-pressure outlet 3 and adapted to be opened by a spring 4, preferably adjustable as indicated, and to be closed by fluid pressure acting on an op erative diaphragm 5 or the like in opposition to the spring 4. The pilot valve may consist of a similar structure, with the addition, however, of a second diaphragm 6 or the like arranged to balance the action of fluid pressure on the disc, or the like constituting the lift valve 7. Fluid from the highpressure supply is admitted, through a duct 8 and an adjustable needle or like valve 9, to the space 10 in the pilot valve between the lift valve 7 and its balancing diaphragm 6 and from there passes by a passage 11 to the space 12 in the main valve where it is free to act on the operative diaphragm 5 of the latter. The operative diaphragm 13 of si lar in GreatBritain may 5, 1928f the pilot valve is, however, acted upon by the low-pressure fluid, a suitable connection 14 fromthe low-pressure outlet 3 being made forthis purpose by a branch 15, this connection also passes steam from the valve 7 to the low pressure side. In their normal position both the main and pilot valves 1 and 7 are open due to the action of their springs 4 and 16, but on high-pressure fluid beingadmitted the mainvalve 1 is closed by pressure; acting on thediaphragm 5 to an extent suflicient to produce the desired reduced pressure on the low-pressure side. Correspondingly the pilotvalve 7 is also partially closed "owing to the action of the reduced pressure on its operative diaphragm 13; It now lthe'reduced pressure should fall, owing, for-example, toincreased rate of consump tion, thepilot valve 7,due to reduction of pressure on the diaphragm 13,":is opened slightly by the spring 16, thus permitting escape of high pressurefluid through the pilot valve Tat a greater rate than can be supplied through theneedle valve 9 and so reducing the pressure acting on the diaphragm 5 of the main valve 1, the opening of which isthereby increased, thus resulting in restoration' of the required pressure on the lowpressure side. Conversely, should this lowpressureincrease an action opposite to that 30 above described-occurs, whereby the aperture of the main valve 1 is reduced and the pressure on the low-pressure side is brought backtoits normal valve. r

Obviously instead of or in combination 5 with any orall of the diaphragms employed in the main and pilot valves pistons may be used. Thusin the pilot valve depicted in Figure 4,- the balancing diaphragm 6 is replaced by a piston 18. This figure also shows not a question of reducing the steam pressure, and hence the steam supply is connected to the inlet 2, whilethe space above the water, the pressure in which will vary in accordance I with the temperature to which the water is raised, is connected to the space 17 in the pilot valve situated in proximity to its operative diaphragm 13. By means of an inlet aperture 19, the passages 14: and 15 are dispensed with and the space above the valve 7 is open to atmosphere through an aperture 20. Thus the rate of steam supply is automatically controlled in accordance with the pressure existing above the water in the boiler, that is to say, in accordancewith the temperature in the boiler.

What Iclaim and desire to secureby Letters Patent of the United States is:

1. A regulating valve comprising in combination a main valve, a spring acting on said main valve in opposition to the direction of v fluid pressure which it is intended to apply thereto, a pilot valve andspring similar'to said main valve and spring and a balancing device for said pilot valve.

2. A regulating valve comprising in combination a main valve, a spring'a'cting on said main valve in opposition, to the direction of fluidpressure which it is intended to apply thereto, an operative diaphragm associated with said main valve, a pilot valve and. spring similar to said main valve and spring, a balancing device for said pilot valve, and a needle valve associated With said pilot valve and adapted to admit fluid pressure to said balancing device.

3. A regulating valve as in'iclaim. 2, in"

which the needle valve serves to admit fluid from the high-pressure side of the main valve to a space communicating both with the pilot valve and with its balancing deviceand also to the operative diaphragm in the main valve.

4. A regulating valve as in claim 2, in which the pilot valve serves to by-pass fluid admitted by the needle valve at a rate which causes variation in the pressure acting on the operative diaphragm of the main valve in accordance with the pressure at the outlet of the main valve.

5. A regulating valve as. in claim 1, in which the balancing device of the pilot valve is constituted by a diaphragm.

6. A regulating valve as in claim 2, in which the pilot valve is fitted with an operative diaphragm and means is provided for admitting fluid from the low-pressure side of the mainvvalveuato said operative diaphragm.

A JOHN DEWRANCE. 

